The invention comprises an erasable product such as an erasable label, a repositionable erasable write-on marker, an erasable sign or similar.
Our PCT patent application GB92/01057 (WO92/22434) discloses an erasable and rewritable label comprising a base layer of contrasting colour and a transparent or translucent upper sheet which can be adhered to the base layer under writing pressure and which label can be erased by wiping a user""s finger or thumb over the top surface of the upper sheet. The invention comprises a unique rewritable label which is erasable for reuse by xe2x80x9cfinger wipe erasurexe2x80x9d.
Our PCT patent application NZ93/00125 (WO94/14148) discloses an improved form of such an erasable product, incorporating a xe2x80x9cwipe-startxe2x80x9d region where the upper sheet and the base layer are not adhesive together, over which wipe-start region a user""s fingers or thumb is placed to begin the finger wipe erasure movement.
Our PCT parent application NZ94/00031 (WO94/24654) discloses an erasable sign comprising a base layer and a transparent or translucent upper sheet; in some cases the upper sheet and base layer may be caused to adhere together by pressure on the upper sheet to display the icon or indicia and the upper sheet may be released from the base layer by finger wipe erasure to erase the icon or indicia, and in other cases the icon or indicia is displayed when the upper sheet is released from the base layer by finger wipe erasure and is erased when the upper sheet is pressed to adhere to the base layer.
It is an object of the invention to provide an improved form of erasable product.
In broad terms the invention comprises an erasable product comprising a backing sheet, a base layer on the backing sheet, and an upper sheet extending over the base layer and fixed in relation to the base layer, which upper sheet and base layer are sufficiently releasably adhesive together under pressure applied manually on the upper sheet to cause the upper sheet and the base layer to adhere in the localised region of said pressure but to allow the upper sheet to move sufficiently relative to the base layer to separate the upper sheet from the base layer when auser""s finger or thumb is wiped across the top surface of the upper sheet, the upper sheet also extending over a xe2x80x9cwipe-startxe2x80x9d region adjacent the base layer in which wipe-start region the upper sheet and the base layer are not adhesive together, over which wipe-start region a user""s finger or thumb may be placed to begin said movement to separate the upper sheet from the base layer, the upper sheet also containing a discontinuity in the upper sheet across a substantial portion of the upper sheet (across the definition of said finger movement) within the wipe-start region or between the wipe-start region and the balance of the upper sheet which extends smoothly over the base layer.
The discontinuity in the upper sheet tends to assist in the formation of a wave or wrinkle, when a user""s fingers or thumb is wiped across the top surface of the upper sheet from the wipe-start region, which will separate the upper sheet from the base layer, erasing any indicia in the erasable window.
The erasable product may comprise a repositionable erasable product such as a repositionable label or message note or a repositionable write-on marker (like a tape flag) or a repositionable erasable sign, having a restrictable contact adhesive on a part of the rear surface of the product enabling the marker or sign to be stuck to a surface and subsequently removed and repositioned.
The erasable product may comprise an erasable and rewri table label or message note or similar having adhesive on all of the rear surface of the product enabling it to be permanently or semi-permanently stuck to in object or item such as a video cassette, computer disc folder or any other objection or item.
Alternatively again the erasable product may comprise part of or be a novelty or other card or item having no adhesive rear surface.
In erasable products of the invention details are written on the upper sheet of the erasable product for example with a blunt instrument such as a blunt stylus, a pen or pencil (preferably the non-marking end so as not to permanently mark the erasable product) or any hard object. To erase the erasable product a user""s finger is wiped under moderate pressure, from the xe2x80x9cwipe-startxe2x80x9d region across the top sheet over the discontinuity in the upper sheet and then over the written details on the product, which are thereby erased.
In erasable products of the invention the upper sheet is preferably translucent to enhance the contrast between the colour of the base layer and the balance of the upper sheet. The upper sheet may additionally or alternatively be tinted with a different colour relative to the colour of the base layer, so that in the cast of a label for example the label normally appears to have the colour of the upper sheet and when written on the writing appears in the colour of the base layer, or in a colour resulting from the combination of the base layer and upper sheet colour. For example, the base layer may be coloured blue and the upper sheet toned yellow, when pressed or adhered together under localized pressure of writing the writing will appear green in contrast to the balance of the yellow upper sheet. The colours may be luminescent or fluorescent. The upper sheet may also be made luminescent or fluorescent or may be lightly embossed with a pattern or logo for example which may be present as a hologram printed onto the upper sheet.
In another form of the invention the erasable product is an erasable sign. The product comprises a contrasting icon or indicia in or below the base layer which icon or indicia is visible through the upper sheet when pressure is applied manually on the upper sheet for example with a blunt writing instrument to cause the upper sheet and the base layer to adhere, and which is made substantially less visible when a user""s finger or thumb is wiped across the top surface of the upper sheet from the wipe-start region across the discontinuity region and then the balance of the top surface of the product to separate the upper sheet from the base layer. The base layer may be formed in the shape of the icon or indicia as a positive image of the icon or indicia, or as a negative image, or the icon or indicia may be printed on a surface beneath the base layer as a positive or negative image and the base layer applied over said surface as a clear or substantially clear coating.
In another form of erasable sign similar to that described above and which is used similarly the base layer may be continuous and a coating to which the upper sheet will nor adhere may be coated over the base layer i.e. the coating is a negative image of the icon or indicia (but could be a positive image). Such a coating may be applied to the underside of the upper sheet instead of to the top of the base layer.
In another form of erasable sign of the invention an icon or indicia is printed on the upper sheet in a colour such that when pressure is applied manually on the upper sheet for example with a blunt writing instrument-to cause the upper sheet and the base layer to adhere the icon or indicia is made substantially less visible, and when a user""s finger or thumb is wiped across the top surface of the upper sheet from the wipe-start region across the discontinuity region and then the balance of the top surface of the product to separate the upper sheet from the base layer the icon or indicia becomes visible. The icon or indicia may be printed on the underside or top of the upper sheet, as a positive or negative image.
In all forms of erasable products of the invention the upper sheet and the base layer may be made non-adhesive together in the wipe-start region by not applying material comprising the base layer beneath the upper sheet in the wipe-start region, or by applying a coating which prevents the upper sheet and base layer from adhering together to the under surface of the upper sheet or the top surface of the base layer, or both, in the wipe-start region.